#!/bin/sh /etc/rc.common
######################################################################
# vim: set ft=bash
# shellcheck disable=2155,3019,3043,3057,3060
######################################################################

START=93

PROG=smp_affinity

log_msg() {

    local irq_name="$1" affinity="$2" irq="$3"

    msg="$(printf "Pinning IRQ($irq) %-24s to CPU ${affinity}\n" "$irq_name")"

    logger -t "$PROG" "$msg"
}

######################################################################
### Takes a comma, space separated, or range list of CPU numbers and
## returns a bitmask of CPUs.
## cpus_to_bitmask "0,1,2,3" -> f
## cpus_to_bitmask "0 1 2 3" -> f
## cpus_to_bitmask "0-3"     -> f
## cpus_to_bitmask "3"       -> 8
#######################################################################

cpus_to_bitmask() {

    local bitmask=0
    # shellcheck disable=2048
    for range in ${*//,/ }; do
        start="${range%-*}"
        end="${range#*-}"
        if [ -z "$end" ]; then
            bitmask="$((bitmask | 1 << start))"
        else
            bitmask="$((bitmask | ((1 << (end - start + 1)) - 1) << start))"
        fi
    done
    printf '%x' $bitmask
}

######################################################################
### Takes a bitmask of CPUs and returns a space separated list of
## CPU numbers.
## bitmask_to_cpus f -> 0 1 2 3
######################################################################

bitmask_to_cpus() {

    [ "${1:0:2}" != "0x" ] && set -- "0x$1"
    local bitmask="$(printf '%d' "$1")"

    local cpus=""
    for i in $(seq 0 63); do
        if [ $((bitmask & 1)) -ne 0 ]; then
            cpus="$cpus $i"
        fi
        bitmask=$((bitmask >> 1))
    done
    echo "${cpus# }"
}

######################################################################
### Sets the affinity of the IRQs with the given name to the given CPU.
## 1st argument: IRQ name ("reo2host-destination-ring1") (req)
## 2nd argument: CPU number (req)
######################################################################

set_affinity() {
    local irq_name="$1" affinity="$2" occurrence="${3:-1}" bitmask irq
    awk -v irq_name="$1" -v occurrence="$occurrence" '
        BEGIN{count=0}
        $NF==irq_name {
            if(++count==occurrence){
                sub(/:$/,"",$1)
                print $1
            }
        }' /proc/interrupts | while read -r irq; do
        $enable_log && {
            log_msg "$irq_name" "$affinity" "$irq"
        }
        bitmask=$(cpus_to_bitmask "$affinity") && echo "$bitmask" >"/proc/irq/$irq/smp_affinity"
    done
}

enable_affinity() {
    # assign 4 rx interrupts to each core
    set_affinity 'reo2host-destination-ring1' 0 1
    set_affinity 'reo2host-destination-ring2' 1 1
    set_affinity 'reo2host-destination-ring3' 2 1
    set_affinity 'reo2host-destination-ring4' 3 1

    # assign 3 tcl completions to last 3 CPUs
    set_affinity 'wbm2host-tx-completions-ring1' 1 1
    set_affinity 'wbm2host-tx-completions-ring2' 2 1
    set_affinity 'wbm2host-tx-completions-ring3' 3 1

    # assign 3 ppdu mac interrupts to last 3 cores
    set_affinity 'ppdu-end-interrupts-mac1' 1 1
    set_affinity 'ppdu-end-interrupts-mac2' 2 1
    set_affinity 'ppdu-end-interrupts-mac3' 3 1

    # assign 4 lan/wan to core 4
    set_affinity 'edma_txcmpl' 3 1
    set_affinity 'edma_rxfill' 3 1
    set_affinity 'edma_rxdesc' 3 1
    set_affinity 'edma_misc' 3 1

    # assign nss_queue0 to 2-3
    set_affinity 'nss_queue0' 2-3 1

    # assign Copy Engine
    set_affinity 'bam_dma' 1 1
    set_affinity 'bam_dma' 2 2
    set_affinity 'bam_dma' 3 3
}

boot() {

    local enable

    config_load smp_affinity

    config_get_bool enable "general" enable 1
    config_get_bool enable_log "general" enable_log 1

    [ "$enable" -eq 1 ] && enable=true || enable=false
    [ "$enable_log" -eq 1 ] && enable_log=true || enable_log=false

    $enable && enable_affinity
}
